Severity of Visual Field Loss at First Presentation to Glaucoma Clinics in England and Tanzania

Pete R Jones,Heiko Philippin,William U Makupa,Matthew J Burton,David P Crabb

doi:10.1080/09286586.2019.1661499

Abstract

ABSTRACTPurpose: To compare severity of visual field (VF) loss at first presentation in glaucoma clinics in England and Tanzania.Methods: Large archives of VF records from automated perimetry were used to retrospectively examine vision loss at first presentation in glaucoma clinics in Tanzania (N = 1,502) and England (N = 9,264). Mean deviation (MD) of the worse eye at the first hospital visit was used as an estimate of detectable VF loss severity.Results: In Tanzania, 44.7% {CI95%: 42.2, 47.2} of patients presented with severe VF loss (< −20 dB), versus 4.6% {4.1, 5.0} in England. If we consider late presentation to also include cases of advanced loss (-12.01 dB to -20 dB), then the proportion of patients presenting late was 58.1% {55.6, 60.6} and 14.0% {13.3, 14.7}, respectively. The proportion of late presentations was greater in Tanzania at all ages, but the difference was particularly pronounced among working-age adults, with 50.3% {46.9, 53.7} of 18–65-year-olds presenting with advanced or severe VF loss, versus 10.2% {9.3, 11.3} in England. In both countries, men were more likely to present late than women.Conclusions: Late presentation of glaucoma is a problem in England, and an even greater challenge in Tanzania. Possible solutions are discussed, including increased community eye-care, and a more proactive approach to case finding through the use of disruptive new technologies, such as low-cost, portable diagnostic aids.

Highlights

Glaucoma is the third leading cause of blindness worldwide, affecting approximately 3.5% of adults aged 40–80 years old.[1]
High levels of late presentation in Tanzania are evident in Figure 2, which shows data from individual eyes: systematically selected to show a representative sample of visual field (VF) loss severities within each population
Peers in England: Overall, 50.3% {46.9, 53.7} of adults of prime working age (18–65 years) presented with advanced or severe VF loss in Tanzania, compared to 10.2% {9.3, 11.3} in England. This corresponds to a Relative Risk ratio for late presentation of 4.9 {4.4, 5.6} for 18–65-yearolds, compared to 4.3 {4.0, 4.6} for individuals age 65+

Summary

Introduction

Glaucoma is the third leading cause of blindness worldwide, affecting approximately 3.5% of adults aged 40–80 years old.[1]. In England[3,4,5], Canada[6], and Australia[7], it is estimated that as many as one in five patients with glaucomatous visual field (VF) loss already has advanced damage in at least one eye by the time they first present to a glaucoma clinic. A prospective study of government-run glaucoma clinics in Botswana found that one in seven individuals was blind at presentation (visual acuity

Methods

Results

Conclusion